The cabinet secretary, Sir Gus O'Donnell, has written to David Cameron to ask him to rein in government spin doctors, saying that some have behaved "unacceptably", it has emerged.
The unusual step came after government sources unleashed an attack on a senior public servant, Jenny Watson, claiming her career was "built on incompetence" and that she was "milking" the taxpayer. The comments last September were interpreted as a sign to other public officials that the coalition was preparing a clearout from the Labour era. But the outspoken and personal nature of the briefing provoked a storm in Whitehall with senior figures – including the chair of the Committee for Standards in Public Life, Sir Christopher Kelly – condemning the language used by the community secretary, Eric Pickles' department. The briefing was given by one of Pickles' special advisers.
Now it has been revealed that O'Donnell wrote to the prime minister following the row. In response to a freedom of information request by PR Week, the Cabinet Office confirmed that O'Donnell wrote to the PM regarding "the role, status or conduct of government special advisers".
PR Week reported that the letter said: "You will have been aware of briefings to the media regarding Jenny Watson. This behaviour is unacceptable. I trust you will agree with me and take necessary action to make sure that people understand this will not be tolerated." Labour has written to O'Donnell calling for those responsible to be identified and sacked.
Asked about the letter, the prime minister's official spokesman said: "Clear rules are in place and we expect people to abide by them. The prime minister is responsible for the appointment of special advisers." O'Donnell refused to comment.
Last year, the Times reported a source in the communities department confirming that Watson's position as a board member of the Audit Commission was not being renewed, saying: "She was begging Mr Pickles to stay on but we are not having someone who built their career on incompetence continuing to milk the taxpayer. She is not fit for the role.
"The Audit Commission has lost its way and the last thing we need is someone like her on board. She has no previous experience outside the public sector. We have had a bonfire of the quangos. Now [we] are having a bonfire of the quangocrats."
The communities department has since refused Ffreedom of information requests to reveal any legal advice it sought after some civil servants reportedly raised concerns that they could be considered defamatory. Watson has not spoken publicly about the row.
The special advisers' code of conduct sets out their role in developing policy, writing speeches, liaising with the party, civil servants and the press. It says: "Special advisers should conduct themselves with integrity and honesty."
There have been wider concerns about the inexperience of some so-called "spads" – special advisers to ministers who specialise in media or policy development. Downing Street restricted the number of media spads to one per cabinet minister, promising to reduce the numbers compared with the Labour government. But some senior figures in Whitehall now believe that has left ministers exposed.
Caroline Flint, the shadow communities secretary, said that any advisers making such comments should be sacked. "It would be disgraceful if the prime minister and local government secretary were protecting the identity of someone responsible for smearing a public official."